Internal combustion engine



March 11, 1941.' I A M lMALLQRY 2,234,267

INTERNAL COMBUSTION ENGINE Filed May ze. 19:59

NAR/0N HALLO/W Patented Mar.i11, 1941 uNirEo srli'rlss PATENT OFFICE 3 Claims.

This invention relates to an internal combustion engine. The invention relates :more particularly to an internal combustion engine in which each power unit comprises a pair of pistons operating in a pair of cylinders which are in continuous communication with each other. The cylinders are provided with separate intake manifolds each controlled by separate throttle valves and intake valves. Each cylinder is given a separate charge, which charges are segregated from each other during the intake and compression strokes of the engine even though the two cylinders are continuously in communication.

One of the main objects of the invention is to prevent the two charges, one for each of the cylinders, from commingling with each other on the intake and compression stroke. This object is achieved by controlling the amount of charge admitted to the two cylinders at any throttle set- 20, ting sol that the pressures in the two cylinders will be the same. In other words, balanced, to prevent .the two charges from commingling on both the intake and compression strokes.

Where the cylinders are the same size, that is, bore, this object is achieved by making the intake ports for each cylinder the same size, the

intake manifolds and venturis for each cylinder the same size, the throttle. valves for the manifolds the same size, and arranging the throttle valves so that they open and close in unison as the engine is throttled.

When the cylinders are of different sizes or unbalanced, the control that admits the charges must'also be unbalanced. For example; if one of the cylinders were smaller than the other, it would be necessary to use a smaller venturi and a smaller throttle valve for vthe smaller cylinder than that used with the larger cylinder so as to keep the pressures on the intake stroke and oompression stroke the same in the two cylinders at all throttle positions.

In the drawing Fig.`1 shows a vertical section through the engine which is the subject matter of this invention and Fig" 2 is a section along the line 2-2 of Fig. l.

The cylindersV l0 and I I, for purposes of 'description -rather than by way of limitation, are

of the same size. The upper ends of the cylinslightly leads piston i3. However, since the pistons l2 and I3 are connected to a common crank of the crankshaft Il they have strokes of equal lengths.

The head of cylinder lll is provided with an electric spark-plug 2t for igniting the fuel and air mixture in the combustion chamber of cylinder lll.

Cylinders lll and ll are provided with intake manifold passageways 2l and 22 respectively of identical sizes. Manifold passageway 2| communicates with 4cylinder` I0 through an intake port controlled by intake valve 6 and manifold passageway 22 communicates with cylinder II by an intake port controlled by intake valve 5. The two intake valves 6 and 5 are opened in unison by cams 8 and 9 respectively and closed in unison by the usual compressionl springs 23.

` Manifold passageway 2l is controlled by butterfly throttle valve 4 and manifold passageway 22 is controlled by butterfly throttle valve 3. Throttle valvesB and 4 are fixed to a common shaft 24 and opened and closed in unison.

'I'he engine is provided with a duplex carburetor, generally designated 25, which is connected with a source of liquid fuel (not shown) in the customary manner. The carburetor is provided with venturis lI and 2 which communicate respectively with manifold passageways 2| and 22.- `Cylinder I I is provided with an exhaust port controlled by exhaust valve I6 which is operated in the well known manner from the same cam shaft that operatesthe intake valve 5.

The carburetor which supplies the fuel and air mixture to cylinder III has an idle bypass I4. When the engine is working under no load or idling an idling fuel mixture is admitted to cyllnder I0 only and nothing lbut air is admitted into the cylinder II. Thus when the engine is idling the power is generated in cylinder Ill only.

The carburetor venturis I and,2 are provided with fuel nozzles or jets 26 and 2l respectively.

Cylinder II is also provided with a fuel injection nozzle I5 which is connected 'to a fuel pump, not shown, in the conventional manner. The use of the injection nozzle I5 is optional. If it is desired to inject the fuel into cylinder Il by injection nozzle I5, then the carburetor for manifold 22 is turned oil so that no fuel is drawn from nozzle 21 and air only passes through venturi 2 and by throttle valve 3.

'I'he two cylinders I0 and II represent one power unit corresponding to the single cylinder of theconventional engine. In other words, if the engine had four pairs of cylinders I0 and II venturis I and 2 are the same size and the same is true of the inlet ports controlled |by valves 5 and 6. When the cylinder Il is working on injection the charge drawn through intake mani- .place over piston I2.

communication 'I ignites the charge over pisfold 22 will consist of aironly and will not become a fuel mixture until the fuel is injected through injection nozzle I5. Naturally, the iniection ofsolid fuel through nozzle I takes place on the compression stroke and the amount of fuelinjected will be regulated so that the volume of fuel is increased or decreased correspondingly as the air charge is increased or decreased by throttle valve 3.

On the intake stroke of the pistons, the vacuums 'in the two cylinders will, be balanced, which causes the vacuum in the one cylinder to oppose the vacuum in the other and prevent the charge in one cylinder from being drawn through passageway 1 into the other cylinder.` This same vcondition exists on the compression stroke of the pistons, because, if the charging pressures are the same in each cylinder, the compression pressures will be the same in each cylinder. balanced compression pressures oppose each other and prevent the charge from one cylinder passing into the other cylinder. Of course, piston I2 leads piston I3 on the compression stroke and there will be a. slight amount of the charge in cylinder III forced over into cylinder II atthe end of the compression stroke of piston I2 but this is not objectionable.l This condition is favorable because atV no time is the mixture in cylinder I0 diluted by the air charge or lean mixtures in cylinder I I. Further, whatever combustible mixture is forced out of cylinder I0 into cylinder II will actas kindling to assist the burning of the leanI :nixture or expand the air that is in cylinder The main object of the invention is to keep the charges segregated so that a combustible mixture can be maintained in cylinder I0 and air alone can be used in cylinder II, which latter condition obtains when the engine is idling, or vary the fuel mixture fromair to a combustible mixture in cylinder II and under all these conditions prevent the charge admitted to cylinder II ronlinmixing with the mixture admitted to cylin- If it is desired to use carburetted mixutres in both cylinders I0 and II the fuel emitted from.

jet 21 may be gasoline, the same as used in cylinder I0 or may be a lower grade fuel if desired.

As the pistons draw inthe two charges and then compress them aspark occursat the sparkplug in cylinder I0 causing an explosion to take The flame passing through ton I3.

From the above, it is evident that there is pro- I d uced an engine having dual cylinders or combustion chambers in continuous communication, each provided with separate means for supplying Naturally,

fuel mixtures which are so controlled that the pressures in the cylinders both on the compression and intake strokes of the pistons are maintained substantially the same so that no commingling of the separate charges in the cylinders takes place either during intake or compression.

I claim 1. In an engine having two cylinders and reciprocating pistons therein, the said cylinders and pistons cooperating to define two combustion chambers, a communication betweenthetwo combustion chambers which is open `continously, separate intake manifolds connected to the intake ports of each of the cylinders, a fuel carburetor connectedto at least one of said manifolds, intake valves for said intake ports, and 1 throttle valves for said intake manifolds, the said throttle valve, intake manifold, and intake port open communicationtbetween the two combustion chambers, a carburetor having a fuel jet and an idling by-pass, an intake manifold connecting the carburetor, fuel jet and idling bypassto the inlet port of one of said cylinders, an `intake manifold connected to the -inlet port of the other cylinder, means for supplying fuel to said last mentioned cylinder whenever the engine is operating under load, throttle valves for said manifolds and intake valves for said intake ports operating to open and close simultaneously whereby the pressure in the intake manifold and in the two cylinders is balanced on the compression and intake strokes of the pistons and the fuel mixture drawn into the one cylinder is segregated from the charge in the other cylinder during the intake and compression strokes of the pistons.

3. In an engine having two cylinders .of equal size and pistons reciprocating in unison therein, the said cylinders and pistons cooperating to define two combustion chambers, a communication between the two combustion' chambers which is open continuously, separate intake manifolds connected to the intake ports o1 each of the cylinders, a fuel carburetor connected to at least oney of said manifolds,vintake valves for said intake ports, and throttle valves for said intake manifolds, the said throttle valve, intake manfold, and intake port and valve for the one cylin- 

